Magento: Increase "Qty" upon cancel a shipped order - magento

Question

I'm on Magento 1.7.0.2. I'm using "Cash On Delivery" as my payment method.I'll tell you exactly the steps That i follow on any order. When an order is placed(Qty decreased 1 item), I create a shipment for it and if customer paid the order grand total price. I create an invoice for that order.
My problem, If an order is placed(Qty decreased 1 item), I create a shipment for this order. If the customer refused to pay, I open this order and "Cancel" it and on this case the "Qty" doesn't increase so How can I make it increase?

Answer 1

If order status is Processing
Create a custom module with observer for 'order_cancel_before' (see example # Change Magento default status for duplicated products change <catalog_model_product_duplicate> to <order_cancel_before>
since <order_cancel_before> is not defined in app/code/core/Mage/Sales/Model/Order.php
You could override/rewrite order model class see e.g http://phprelated.myworks.ro/how-to-override-rewrite-model-class-in-magento/
In your local module do
public function cancel()
{
if ($this->canCancel()) {
Mage::dispatchEvent('order_cancel_before', array('order' => $this));
$this->getPayment()->cancel();
$this->registerCancellation();
Mage::dispatchEvent('order_cancel_after', array('order' => $this));
}
return $this;
}
Or you could create a new method increaseProductQty() in your model and copy the code below into it (this way you would not need an observer). Then replace the line Mage::dispatchEvent('order_cancel_before'... with $this->increaseProductQty()
In your observer method (pseudo code)
$curr_date = date('Y-m-d H:i:s');
$order = $observer->getEvent()->getOrder();
foreach ($order->getItemsCollection() as $item)
{
$productId = $item->getProductId();
$qty = $item->getQty();
// you need to check order status to make sure it processing
//$order->getStatus() (assuming you are canceling entire order)
//$order->getPayment();
$product = Mage::getModel('catalog/product')->load($product_id);
$stock_obj = Mage::getModel('cataloginventory/stock_item')->load($product_id);
$stockData = $stock_obj->getData();
$product_qty_before = (int)$stock_obj->getQty();
$product_qty_after = (int)($product_qty_before + $qty);
$stockData['qty'] = $product_qty_after;
$productInfoData = $product->getData();
$productInfoData['updated_at'] = $curr_date;
$product->setData($productInfoData);
$product->setStockData($stockData);
$product->save();
}
If you have issue with updating stock see Set default product values when adding new product in Magento 1.7
Reference http://pragneshkaria.com/programatically-change-products-quantity-after-order-cancelled-magento/
If order status is Pending
Take a look at System > Configuration > Inventory
Set Items’ Status to be In Stock When Order is Cancelled — Controls whether products in pending orders automatically return to the stock if orders are cancelled. Scope: STORE VIEW.
Read more #
How to Manage Magento Store Inventory?
ADMIN: System → Configuration → Inventory Tab

Answer 2

Thanks to R.S as he helped me more & more.
I followed all instructions on R.S's reply https://stackoverflow.com/a/13330543/1794834 and I've only changed the observer code. Here is the observer code that worked with me on Magento 1.7.0.2.
$curr_date = date('Y-m-d H:i:s');
$order = $observer->getEvent()->getOrder();
foreach ($order->getItemsCollection() as $item)
{
$productId = $item->getProductId();
$qty = (int)$item->getQtyOrdered();
$product = Mage::getModel('catalog/product')->load($productId);
$stock_obj = Mage::getModel('cataloginventory/stock_item')->loadByProduct($productId);
$stockData = $stock_obj->getData();
$product_qty_before = (int)$stock_obj->getQty();
$product_qty_after = (int)($product_qty_before + $qty);
$stockData['qty'] = $product_qty_after;
/*
* it may be case that admin has enabled product add in stock, after product sold,
* he set is_in_stock = 0 and if order cancelled then we need to update only qty not is_in_stock status.
* make a note of it
*/
if($product_qty_after != 0) {
$stockData['is_in_stock'] = 1;
}else{
$stockData['is_in_stock'] = 0;
}
$productInfoData = $product->getData();
$productInfoData['updated_at'] = $curr_date;
$product->setData($productInfoData);
$product->setStockData($stockData);
$product->save();
}